Oxygen reduction reaction (ORR) kinetics through different solvents of the non-aqueous electrolyte in Li-air (O2) batteries in both the gas and solution phases: A DFT study

We performed DFT calculations to investigate the role of solvent of the non-aqueous electrolytes for the oxygen reduction reaction (ORR) kinetics in Li-air batteries. The calculated results on structural, thermodynamic and vibrational properties revealed that dimethyl sulfoxide (DMSO) is the most stable solvent among DME, DMSO, and MeCN of non-aqueous electrolytes. The LiCF3SO3/DMSO electrolyte was primarily assumed to be the most favorable for ORR kinetics from the IR analysis. We calculated thermodynamic properties of the ORR reactions held during the formation of superoxide (O2−) ion and the sole discharge products lithium peroxide (Li2O2), and lithium oxide (Li2O) to study the ORR kinetics of the stable salt LiCF3SO3 with three solvents namely dimethoxyethane (DME), dimethyl sulfoxide (DMSO), and acetonitrile (MeCN). The thermodynamic properties of the ORR reaction signified the best role of LiCF3SO3/DMSO electrolyte compared to LiCF3SO3/DME and LiCF3SO3/MeCN both in the gas and solution (water) phases.